Evaluation of Endogenous Allergens for the Safety Evaluation of Genetically Engineered Food Crops

University of Nebraska - Lincoln DigitalCommons@University of Nebraska - Lincoln Faculty Publications in Food Science and Food Science and Technology Department Technology 2013 Evaluation of Endogenous Allergens for the Safety Evaluation of Genetically Engineered Food Crops: Review of Potential Risks, Test Methods, Examples and Relevance Richard E. Goodman University of Nebraska-Lincoln, [email protected] Rakhi Panda University of Nebraska-Lincoln Harsha Ariyarathna University of Peradeniya, Sri Lanka Follow this and additional works at: http://digitalcommons.unl.edu/foodsciefacpub Part of the Bioresource and Agricultural Engineering Commons, Food Biotechnology Commons, and the Other Biomedical Engineering and Bioengineering Commons Goodman, Richard E.; Panda, Rakhi; and Ariyarathna, Harsha, "Evaluation of Endogenous Allergens for the Safety Evaluation of Genetically Engineered Food Crops: Review of Potential Risks, Test Methods, Examples and Relevance" (2013). Faculty Publications in Food Science and Technology. 149. http://digitalcommons.unl.edu/foodsciefacpub/149 This Article is brought to you for free and open access by the Food Science and Technology Department at DigitalCommons@University of Nebraska - Lincoln. It has been accepted for inclusion in Faculty Publications in Food Science and Technology by an authorized administrator of DigitalCommons@University of Nebraska - Lincoln. Reproduced here under the terms of the ACS AuthorChoice usage agreement. Article pubs.acs.org/JAFC Terms of Use Evaluation of Endogenous Allergens for the Safety Evaluation of Genetically Engineered Food Crops: Review of Potential Risks, Test Methods, Examples and Relevance Richard E. Goodman* Food Allergy Research and Resource Program, University of NebraskaLincoln, 143 Food Industry Complex, Lincoln, Nebraska 68583-0955, United States Rakhi Panda Food Allergy Research and Resource Program, University of NebraskaLincoln, 143 Food Industry Complex, Lincoln, Nebraska 68583-0955, United States Harsha Ariyarathna Department of Veterinary Pathobiology, University of Peradeniya, Peradeniya, Sri Lanka ABSTRACT: The safety of food produced from genetically engineered (GE) crops is assessed for potential risks of food allergy on the basis of an international consensus guideline outlined by the Codex Alimentarius Commission (2003). The assessment focuses on evaluation of the potential allergenicity of the newly expressed protein(s) as the primary potential risk using a process that markedly limits risks to allergic consumers. However, Codex also recommended evaluating a second concern, potential increases in endogenous allergens of commonly allergenic food crops that might occur due to insertion of the gene. Unfortunately, potential risks and natural variation of endogenous allergens in non-GE varieties are not understood, and risks from increases have not been demonstrated. Because regulatory approvals in some countries are delayed due to increasing demands for measuring endogenous allergens, we present a review of the potential risks of food allergy, risk management for food allergy, and test methods that may be used in these evaluations. We also present new data from our laboratory studies on the variation of the allergenic lipid transfer protein in non-GE maize hybrids as well as data from two studies of endogenous allergen comparisons for three GE soybean lines, their nearest genetic soy lines, and other commercial lines. We conclude that scientifically based limits of acceptable variation cannot been established without an understanding of natural variation in non-GE crops. Furthermore, the risks from increased allergen expression are minimal as the risk management strategy for food allergy is for allergic individuals to avoid consuming any food containing their allergenic source, regardless of the crop variety. KEYWORDS: genetically modified, IgE, food allergy, soybean, maize, risk management ■ INTRODUCTION defensible hypotheses related to the introduced gene, gene Genetically Engineered (Genetically Modified) Crops. products, and, if generated, metabolites. In addition, potential ff We have used the term genetically modified (GM) here as the unintended e ects are to be evaluated on the basis of more commonly recognized term, but are restricting the agronomic characteristics, compositional analysis, and evalua- definition to mean those engineered by insertion of a specific tion of key (species specific) nutrients, antinutrients, allergens, sequence of DNA, rather than the broader genetic and toxins.1 Approvals of some specific GM crops for modifications that occur through wide-genetic crosses or importation or cultivation have been delayed for years in the chemical and radiation mutagenesis. Development of a strategy European Union (EU) and some other countries due to and regulations for ensuring that foods from GM crops are as questions related to possible changes in endogenous allergen safe as their conventional counterparts occurred before the first levels, even though these same varieties have been approved in plants were allowed into commercial production. The the United States, Canada, and many other countries foundation of the assessment is the recognition that there is a (unpublished comparison of approvals recorded at www.cera- long history of safe consumption of commonly consumed plant species; there is natural variation in the composition of foods produced from these organisms; and there are specific Special Issue: Safety of GM Crops: Compositional Analysis nutrients, antinutrients, toxins, and allergens in the commonly Received: February 28, 2013 consumed species.1 The safety assessment therefore focuses on Revised: July 14, 2013 characterizing the intended modification with specific tests for Accepted: July 14, 2013 allergenicity or toxicity required on the basis of scientifically Published: July 15, 2013 © 2013 American Chemical Society 8317 dx.doi.org/10.1021/jf400952y | J. Agric. Food Chem. 2013, 61, 8317−8332 Journal of Agricultural and Food Chemistry Article gmc/org for global approvals vs www.GMO-Compass.org for the transformed plant, and progeny as the parental line is rarely EU approvals). We are not aware of any adverse human health completely homozygous at all loci. The selected GM plants are events that have occurred due to the consumption of foods tested for gene stability, performance under various field produced from any approved GM event. Yet the search for conditions, and production of nutrients that are typical of the even minor differences between every new GM and its nearest specific crop to ensure performance. Following the proof of a genetic relative continues. Therefore, we have provided a brief specific GM trait is useful; it will likely be bred into plants with review of the genetic and compositional complexity of the host diverse genetic backgrounds to provide optimum production plants (gene recipient), modification methods, review risks of when grown in very different environments in North and South food allergy, and present new data from three of our studies America, Asia, Australia, Africa, and Europe. Plant geneticists evaluating natural variation in endogenous allergens in maize have only relatively recently begun to be able to document and and in soybean to consider the relevance for evaluating fully understand the genetic differences that exist in similar- endogenous allergen levels in GM crops as part of regulatory appearing varieties of the same species. The maize genome is requirements. thought to include roughly 20500 genes.5 There are few data Overview of GM Crop Development. The first comparing genomes of varieties of crops. However, a genome commercial production of GM crops developed and approved and breeding study of two inbred maize lines, B73 and Mo17, for use in food, feed, and fiber was in 1996, primarily in the estimated a complete comparison would show up to 10000 United States and in Canada, Argentina, and Australia.2 These short, nonshared genetic fragments or chromosomal rearrange- GM plants were developed by transformation of commonly ments between the inbred lines. However, following cross- used food crop varieties by insertion of relatively short pollination, the hybrids produce higher yields, with larger ears, segments of DNA encoding from one to a few proteins from and the plants are adapted to more diverse growing conditions.5 naturally occurring bacteria or plant sources. Expression of the Grain from these hybrids is used for food and feed purposes introduced genes has provided increased resistance to specific similar to uses of grain from the individual inbred parents. The insects, tolerance to commonly used herbicides, resistance to soybean genome includes more than 10000 protein coding specific viruses, or delayed ripening of soft fruits.3 Although genes.6 Although Glycine max (cultivated soybean) and Glycine hundreds of different GM plants have been partially or fully soja (wild soybean) have many divergent genes and are developed, a few traits dominate the commodity market, have generally self-pollinated, the plants can be manually cross- been bred into genetically diverse varieties, and have been pollinated and produce viable progeny.6 Wide genetic crosses widely adopted in many additional countries. Approved GM with wild relatives, such as G. max and G. soja, provide genetic crops were grown on approximately 160 million hectares in 29 diversity that may be useful to introduce disease and stress countries in 2011.4 resistance, but their introduction requires many rounds of Understanding the

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